Before digital images can be stored or transmitted over a network, each digital image is encoded into an image format. A number of image formats for encoding digital images have been developed over the years.
Graphics Interchange Format (GIF) is an image format that was introduced in 1987. GIF images can be compressed without the loss of data using a lossless compression technique. However, the GIF format allows a palette of a maximum of 256 colors for each frame. Therefore, GIF is primarily used for the display of simple images and websites.
Joint Photographic Expert Group (JPEG) was subsequently introduced in 1992, and is one of the most commonly used formats for storing images. JPEG format is compatible with a majority of image processing applications on the market today. In addition, JPEG format is compatible with most hardware devices, making it easy to print images in JPEG format. Moreover, the size of JPEG images can be significantly reduced via lossy compression, making this file format suitable for transferring images over the Internet. Therefore, there are a number of advantages of the JPEG image format.
Another image file format that is commonly used is Portable Network Graphics (PNG). The first version of the PNG specification was released in 1996, and PNG subsequently became an International Standard in 2003. However, since PNG is a lossless file format, the transmission of an image stored in the PNG format will generally consume more bandwidth than an image stored in the JPEG format. Moreover, since PNG is a more recent file format, the support for PNG by older web browsers is limited. Therefore, JPEG remains the most popular format for transferring images over the Internet.